LEWISVILLE (CBSDFW.COM) – Rescuers In Lewisville are on the scene of a serious crash involving a school bus and at least two vehicles.

The accident happened on Highway 121 Business and Railroad Street, just east of Interstate-35E and south of Main Street.

The school bus was empty, besides the driver.

There are reports that the driver of one of the vehicles ran a red light and hit the school bus.

The bus driver was one of two people taken to the Medical Center of Plano by air ambulance. Another driver was transported to the Medical Center of Lewisville by ground ambulance. All of the victims reportedly have serious injuries.

The southbound lanes of Highway 121 are being diverted and only one northbound lane is open.

CBS 11 News has crews on the ground and in the air and will have more information as it becomes available.